• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.149-150
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• 2006

Displayed result that handle particle contaminant and hydrospace organism included in number of ballast that is happened in ship using automatic back washing filter. Reason that remove first contaminant that is included in number of ballast is that heighten processing effect of after processing process. of the filter. Another advantage is to drop oft the solids with controlling revolution of drum screen in pretreatment filtration process. The fact that it is easy to attach and detach a several type of screen for getting the expected water quality is another advantage. Filter rotation speed at 1.0rpm is filter resistance 3.0bar and 3.0rpm is filter resistance 2.8bar. Filter out impurities from ballast water over 6.0rpm is filter resistance 2.6bar and 10rpm is filter resistance 2.5bar. Filtration system removal aquatic organism over $80{\mu}m$ in ballast water. This study shows that the filtration treatment system has a potential for the treatment of ballast water.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.127-133
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• 2020

Most sewage treatment plants located offshore are discharged to the shore either directly or through rivers. Therefore, the water quality of the treated water discharged from the sewage treatment plant affects the water quality of the river water discharged to the river and the ocean. In this study, field surveys and numerical simulations were conducted to investigate the effect of treated water from the sewage treatment plant adjacent to the coastal environment. As a result of analyzing the water quality and sediment quality with the samples collected from the river and the estuary where the treated water was discharged to understand the impact on the coast, the treated water discharged from the sewage treatment plant was discharged to the river without exceeding the design criteria. However, the water quality discharged to the shore through estuaries was more contaminated than treated water. The cause of water quality deterioration of coastal effluent is due to the sedimentation of estuary temporarily by longshore sediment sransport which appeared around the estuary, the occurrence of estuary obstruction, and the increase of stagnant time in the estuary. As it was released and discharged, it was analyzed to affect the water quality, water quality and marine life around the estuary. Therefore, in the case of the east coast where the longshore sediment transport is strong, when planning the sewage treatment facility discharged to the ocean, it is necessary to closely examine the water quality change of the river water in the treated water such as the river mouth occlusion by the longshore sediment transport.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.235-247
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• 2012

BACKGROUND: Gohyeon Stream is the municipal eco-stream of 7.1km in total length which flows through the downtown area of Gohyeon in Geoje city, rising from the watershed of Mundong Water Fall. Gohyeon district in Geoje city has been a rapid growing area centering in Geoje city and then experienced an rapid increase in population. Large amounts of sewage pollutants have been spewed into Gohyeon Stream from its tributaries, due to the lack of sewer system. Gohyeon Stream is laced with unhealthy levels of fecal coliform (FC). Restoration of water quality in Gohyeon Stream is no less inevitable in behalf of its ecosystem and the citizen. In this study, the water quality of Gohyeon Stream and its tributaries was examined temporally and spatially, and their relationships were comparatively analyzed to give useful basic data applying to a restoration project of the water quality of Gohyeon Stream. METHODS AND RESULTS: The samples ware taken at 20 points in Gohyeon Stream and 19 points in its tributaries during the rainy and dry seasons, respectively, and examined on the parameters of pH, temperature, salinity, dissolved oxygen (DO), suspended solid (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN; $NH_3$-N, $NO_3$-N, $NO_2$-N), disolved inorganic phosphorus (DIP; $PO_4$-P) and FC. The data were analyzed using a comparative analysis and Pearson's correlation analysis among the parameters. During the rainy season, the concentration of SS was high in the upper region of Gohyeon Stream, and the concentrations of COD, DIN and DIP were low in the upper region and high in the middle and lower regions. During the dry season, the concentration of SS was low and the concentrations of COD, DIN, DIP and FC were high in all regions. The Pearson's correlation analyses showed that the relationships between DO and FC, COD and DIP, and DIN and FC during the rainy season as well as between DO and DIN, SS and FC, COD and DIP, and DIN and DIP during the dry season were significant. CONCLUSION: During the rainy season, the upper region of Gohyeon Stream flowed the high level of SS, the middle region the high level of nutrients due to an agricultural run-off, and the lower region the high level of nutrients due to a sewage inflow. During the dry season, the water quality of Gohyeon Stream was directly and sensitively influenced on the inflow of sewage from the tributaries.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.324-332
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• 2014

In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.127-134
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• 2014

Gonad maturation of Manila clam, Ruditapes philippinarum was induced in this study using a recirculation system over 8 weeks in early spring. Clams used in the experiment were collected in $15^{th}$ April 2010 from the west coast of Korea, as the surface water temperature remained $11^{\circ}C$. To induce gametogenesis and subsequent maturation seawater temperature was elevated $1^{\circ}C$ per day over 10 days to reach $20^{\circ}C$. For the experiment, clams were raised in 120 L quadrangle tank maintained with re-circulated seawater system over 57 days. Water quality parameters including the water temperature, salinity dissolved oxygen, ammonium ion and nitrate levels in the tanks were monitored daily. Mixture of concentrated microalgae including Tetraselmis, Isochrysis, Pavlova and Thalassiosira weissflogii was supplied to clams twice a day, and quantity of the daily ration was adjusted as 3% of clam body dry weight. Histology was applied to examine gonad maturation. Daily monitoring of the water quality parameters indicated that the recirculation system supplied suitable environment to Manila clam; the nitrogenous components stayed below toxic levels (< 0.2 mg/L). At the beginning of the study, clams were mostly in early developing stage. As the seawater temperature reached $20^{\circ}C$, 10 days after the experiment, 20% of clams reached late development at 12 days. First ripe clams were observed at 42 days and 40% of clams were in ripe and ready for spawning at the end of study, 57 days after the experiment. In this study, gametogenesis of Manila clam was successfully induced by elevating water temperature and supplying commercially produced microalgae in a recirculation tank system.

• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.140-148
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• 2003

On the basis of factor analysis, stations were grouped according to their similar characteristics of seawater quality. The data for factor analysis were collected from the 15 stations from Dukryang Bay to Ulsan Bay on the southern cost of Korea. The study was based on the data from 1991 to 2000. The 8 water quality items analyzed were temperature, salinity, pH, DO, COD, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus), and SS (suspended solid). Analysis of 6 water quality items including DO with the exception of temperature and salinity showed that 15 stations were grouped into two zones, i.e., the western and the eastern coast, by the axis of Samcheonpo-Jinju Bay-south of Geoje, 3 seawater zones in all. The adjacent stations to the southward or northward but not those to the eastward or westward were classified into the same group. On the analysis of all of the 8 water quality items, the stations of Dukryang Bay and Goheung; and those of Onsan and Ulsan Bay were classified into the same group. Yeosu and Namhae stations were sectioned into 1 group on the all seawater quality items but DIP, Samcheonpo and south of Geoje stations another group on all seawater quality items but water temperature, and Masan and Busan stations in the other group on all seawater quality items but DO. The stations from Dukryang Bay through Goheung to east of Geoje were grouped together on the COD item, and this showed somewhat different tendency in other seawater quality items.

• Proceedings of KOSOMES biannual meeting
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• 2001.05a
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• pp.105-133
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• 2001

World trade has been increasing continuously in total volume, on the other hand, environmental protection on sea and conservation of fishery resources has been rising up the major issue. All of the world are pushing their efforts two major purposes to the full, one is taking competitive place in marine transportation throughout the world and another Is environment protection. Pusan Port as world leading Port put its all effort in bring more ocean going vessels and securing their traffic route by providing them more information related marine traffics through PTMS in port. During two years of operation, statistics of marine traffic accidents showed that many dynamic casualties such as collisions, groundings, and rammings has been decreased. However, due to increasing cargo volume, limited water area and unpredictable weather condition, potential risks still exist high. In this paper, in order to maximize the efficiency of PTMS and reduce various risks in the future, we examine risk factors over operational results and experience, and propose reasonable operational methods of PTMS.

• Journal of Fisheries and Marine Sciences Education
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• v.16 no.2
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• pp.227-237
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• 2004

Recently development trends in information technology expand the activity boundaries for human living beyond coastal zones. These rapid changes of paradigm are stimulating scientists and strategists to be encouraged in making adequate model for marine geographic information system (MGIS) and their applications. Coastal zones are places which are affected by many factors, such as water quality, tide, wave, atmosphere, population, industry, etc. Therefore information related to the coast has to be integrated and analyzed for managing it efficiently. GIS-based Ocean Informatics is suited for those purposes and used in the study for establishing and managing coastal geographic and environmental information system. This paper reviews the properties of ocean and coastal spaces, then defines some MGIS related terminologies for clarifying the scope of MGIS boundaries. In this study, coastal geographic information is established by digital geographic information and digital terrain information. Digital coast chart having information on digital chart and map can merge and analyze various coastal information and can be a useful tool for the coastal integrated management.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1220-1227
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• 2001

The condensation pressure drop fur refrigerant R-22 flowing in the plate and shell heat exchanger were investigated experimentally in this study. Two vertical counterflow channels were formed in the exchanger by three plates of commercial geometry with a corrugated trapezoid shape of a chevron angel of $45^{\circ}$. The condensing R-22 flowing down in one channel exchanges heat with the cold water flowing up in the other channel. The effects of the mean vapor quality, mass flux, average imposed heat flux and system pressure of R-22 on the pressure drop were explored in detail. The quality change of R-22 between the inlet and outlet of the refrigerant channel ranges from 0.03 to 0.05. The present data showed that pressure drop increases with the vapor quality. At a higher mass flux, pressure drop is higher for the entire range of the vapor quality. Also, a rise in the average imposed heat flux causes an slight increase in the Pressure drop. Finally, at a higher system pressure the pressure drop is found to be slightly lower. Correlation is also provided for the measured pressure drops in terms of the friction factor.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.313-318
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• 2007

Monitoring for the quality of coastal water is necessary to improve its biological resources and to maintain healthy environments. We measured the concentrations of phenols, nine polychlorinated biphenyls (PCBs), tributyltin (TBT) in surface water at 5 stations and the concentrations of mercury (Hg), chromium (Cr (VI)), cadmium (Cd), lead (Pb) in surface water of 10 stations in Tongyeong marine ranching ground of Korea in August, 2003. The concentrations of analytes were determined as follows: phenols: 1.6$\sim$2.8 ppb, PCBs: not detected (ND), Hg: <0.1 ppb, Cr (VI): 0.01$\sim$5.32 ppb, Cd: ND$\sim$0.41 ppb and Pb: 0.43$\sim$2.60 ppb. These concentrations satisfied the standards of human health protection in coastal water by Ministry of Environment, Republic of Korea as follows: phenols; 5 ppb, PCBs: 0.5 ppb, Hg: 0.5 ppb, Cr (VI): 50 ppb, Cd: 10 ppb and Pb: 50 ppb. TBT was not listed in the standards. The concentrations of Sn in TBT analyzed in sea water of Tongyeong marine ranching ground were in the range of ND$\sim$0.0273 ppb which are similar with the values of 8$\sim$35 ng Sn $L^{-1}$ (0.008$\sim$0.035 ppb) in Chinhae Bay studied by Shim et al.. Therefore, the quality of sea water in Tongyeong marine ranching ground was safe enough to protect human health.